Airborne pollution particles have been shown to translocate from the mother’s lung to the fetal circulation, but their distribution and internal placental-fetal tissue load remain poorly explored. Here, we investigated the placental-fetal load and distribution of diesel engine exhaust particles during gestation under controlled exposure conditions using a pregnant rabbit model. Pregnant dams were exposed by nose-only inhalation to either clean air (controls) or diluted and filtered diesel engine exhaust (1 mg/m3) for 2 h/day, 5 days/week, from gestational day (GD) 3 to GD27. At GD28, placental and fetal tissues (i.e., heart, kidney, liver, lung and gonads) were collected for biometry and to study the presence of carbon particles (CPs) using white light generation by carbonaceous particles under femtosecond pulsed laser illumination. CPs were detected in the placenta, fetal heart, kidney, liver, lung and gonads in significantly higher amounts in exposed rabbits compared with controls. Through multiple factor analysis, we were able to discriminate the diesel engine exposed pregnant rabbits from the control group taking all variables related to fetoplacental biometry and CP load into consideration. Our findings did not reveal a sex effect, yet a potential interaction effect might be present between exposure and fetal sex. The results confirmed the translocation of maternally inhaled CPs from diesel engine exhaust to the placenta which could be detected in fetal organs during late-stage pregnancy. The exposed can be clearly discriminated from the control group with respect to fetoplacental biometry and CP load. The differential particle load in the fetal organs may contribute to the effects on fetoplacental biometry and to the malprogramming of the fetal phenotype with long-term effects later in life.

中文翻译：

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反复暴露于稀释柴油机尾气后孕兔模型中碳颗粒的胎盘-胎儿分布

空气中的污染颗粒已被证明可以从母亲的肺部转移到胎儿循环中，但对它们的分布和胎盘-胎儿内部组织负荷的研究仍然很少。在这里，我们使用怀孕的兔子模型在受控暴露条件下研究了妊娠期间柴油发动机排气颗粒的胎盘-胎儿负荷和分布。从妊娠日 (GD) 3 到 GD27，怀孕的母鼠仅通过鼻子吸入清洁空气（对照）或稀释和过滤的柴油机废气 (1 mg/m3)，每天 2 小时，每周 5 天。在 GD28，收集胎盘和胎儿组织（即心脏、肾脏、肝脏、肺和性腺）用于生物测定，并使用飞秒脉冲激光照射下碳质颗粒产生的白光来研究碳颗粒 (CP) 的存在。与对照组相比，暴露的兔子在胎盘、胎儿心脏、肾脏、肝脏、肺和性腺中检测到的 CP 含量明显更高。通过多因素分析，我们能够将暴露于柴油机的孕兔与对照组区分开来，同时考虑到与胎儿胎盘生物测定和 CP 负荷相关的所有变量。我们的研究结果并未揭示性别效应，但暴露与胎儿性别之间可能存在潜在的相互作用效应。结果证实母体吸入的 CP 从柴油发动机尾气转移到胎盘，这可以在妊娠晚期的胎儿器官中检测到。在胎儿胎盘生物测定和 CP 负荷方面，可以清楚地将暴露者与对照组区分开来。